Application note

Table of statistical corrections according to Feller

How efficient are you at capturing viable particles — colony forming units (CFUs) — on your media surfaces? Statistical calculations using Feller’s formula demonstrate that the design of the BioCapt® Microbial Impactor improves biological collection efficiencies in microbial air sampling. With precision-cut slits to ensure laminar flow, the Impactor maximizes biological collection efficiencies for viable particles in accordance with ISO 14698-1/Annex B for microbial air sampling in cleanrooms and associated controlled environments.

This application note will help you:

Understand calculated statistical results using Feller’s formula.

Solve problems that arise in cleanrooms and associated controlled environments for viable particles when sampling for microbial air contaminants.

Learn how the design of the BioCapt Microbial Impactor helps improve your biological efficiencies at laminar airflows of 25–50 L/min and 100 L/min.

Interested in learning more? Complete the form on the right side of this page to receive a free copy of the Table of statistical corrections according to Feller for the BioCapt Microbial Impactor in microbial air sampling application note.

Abstract

The "Table of statistical corrections according to Feller for the BioCapt®Microbial Impactor in microbial air sampling" is based on the principle that, as the number of viable particles — colony forming units (CFUs) — impact on an agar plate increases, the probability that viable particles will enter unoccupied space decreases. In this application note, the values within the table are shown at flow rates of 25–50 L/min and 100 L/min. BioCapt Microbial Impactors are used on all Particle Measuring Systems microbial instruments, including the MiniCapt® Mobile Microbial Air Sampler and the MiniCapt® Remote Microbial Air Sampler. The BioCapt Single-Use has the same pattern of the BioCapt Microbial Impactor and therefore, the Feller’s table is applicable to this unique BioCapt Single-Use Impactor for 25-50 L/min flow rates.The Impactor’s design enables the capture of microbiologically viable particles on a suitable media surface for incubation and enumeration. These values represent calculated statistical results made using Feller’s formula (Feller, 1950).